I dug insanely deep, says Tiafoe after Anderson upset

Melbourne - Frances Tiafoe rolled up his white shirt's right sleeve, flexed his biceps and slapped the muscle five times. Then he pounded his chest and yelled, "Yeah! Let's go! Let's go! Come on!"

Forgive the young American's exuberance. This was, after all, the biggest victory of his nascent career.

Down a set and 3-0 in the second, the 20-year-old Tiafoe came back to stun two-time Grand Slam finalist and No 5 seed Kevin Anderson of South Africa 4-6, 6-4, 6-4, 7-5 on Tuesday in the Australian Open's second round.

"I went to a different place. I dug insanely deep," the 39th-ranked Tiafoe said during an on-court interview. "It's all about competing. Guys are so good. It's just about how badly you want it. I want it real bad."

It helped that Anderson's best attribute, his intimidating serve, slowed down along the way because of problems with his right arm. Anderson was repeatedly visited by a trainer during changeovers and he lost about 10 kph on his first serves as the match wore on.

Anderson was the runner-up at Wimbledon last year and at the US Open in 2017 and had won all three previous match-ups against Tiafoe.

But Tiafoe ended a six-match losing streak against top-10 opponents and is now into the third round at a major for the second time, equalling his best showing.

Defeat Andreas Seppi of Italy next, and Tiafoe would make his debut in the second week of a Grand Slam.

He turns 21 on Monday and said: "If I'm playing on that day and beat somebody, that's the best present I can get."